We want to welcome our viewers in the United States and around the world. I'm Wolf Blitzer. You're in THE SITUATION ROOM.

Breaking now, the Washington, D.C., police chief says the overwhelming response to a shooting scare at the U.S. Navy Yard here in Washington shows the city is well-prepared for anything that might happen. A 911 call led to a lockdown and raw fear, as the nation is on alert for a possible terror attack around the July 4 holiday weekend.

Tonight, we're getting new information about security precautions here in the U.S. and around the world. I will ask Senator James Lankford what he's learning as the leading member of the House -- of the Senate Homeland Security and Intelligence Committees. And our correspondents and analysts, they are all standing by as we cover all the news breaking right now.

PAMELA BROWN, CNN JUSTICE CORRESPONDENT: Well, Wolf, the outpouring of law enforcement at the Navy Yard today reflects the sensitivity heading into the holiday weekend with the heightened terror threat, combined with the fact that there had been a shooting there in the past.

(BEGIN VIDEOTAPE)

BROWN (voice-over): Within minutes of the first report of shots fired inside Washington's Naval Yard, parts of the nation's capital were thrown into panic.

UNIDENTIFIED MALE: Car three respond on the active shooting.

BROWN: The entire complex locked down, as hundreds of police, SWAT teams and federal investigators swarm the scene, blocking streets as helicopters hovered overhead, inside the same building where a gunman killed 12 two years ago, chaos.

UNIDENTIFIED MALE: Someone came up on the floor yelling to get out of the building, stay away from the cafeteria.

BROWN: For nearly three hours, police moved floor by floor, through Building 197, searching for a gunman, clearing floors, then leading stranded workers out with their hands up.

Across town, the White House blocked streets and canceled tours, at the Capitol, enhanced security. By 10:15, police gave the all- clear, later saying there was a lone 911 call reporting the sounds of gunshots.

CATHY LANIER, DISTRICT OF COLUMBIA POLICE CHIEF: We take every event here in Washington very serious, and our posture remains extremely high.

BROWN: While today's overwhelming response came in part because of the eerie similarity to the Naval Yard shooting rampage two years ago, sources say it was also a result of fears throughout law enforcement of the possibility of a July 4 terror attack coming after increased chatter by ISIS supporters online and calls by the terror group to strike in the West.

Police in Washington, New York and other major cities say they are already increasing security around holiday events.

JOHN MILLER, NYPD DEPUTY COMMISSIONER: This may be potentially the most complex counterterrorism overlay for this event ever. Again, that is not driven by any information or particular threat as much as it's driven by the unfolding of world events.

(END VIDEOTAPE)

BROWN: So that was in New York.

Back here in Washington, adding to today's fears, at the same time that the Navy Yard was on lockdown, police in New Jersey were investigating a bomb threat at a mosque. That turned out to be a hoax.

But at the time, with terror concerns, law enforcement of course did not want to take any chances -- Wolf.

BLITZER: As they shouldn't. All right, Pamela, thank you. Let's bring in our justice reporter, Evan Perez. He was there at

the scene during that Navy Yard lockdown.

What did you experience, Evan?

EVAN PEREZ, CNN JUSTICE CORRESPONDENT: Well, Wolf, the fear was palpable, and especially from employees who went through that incident in 2013, where 12 people were killed.

And certainly Building 197, which was the epicenter of today's scare, was -- is right next door to a very public area with supermarkets and restaurants. And that's where employees went today. They gathered there. You could see them. A few of them were crying, they were shaking. The fear was real.

And also for law enforcement that responded and saw that terrible scene inside Building 197 last time, they also were reacting to the same thing. The fear was real. And thank God it didn't turn out to be what they thought.

BLITZER: That's true. Thank God, indeed.

Now, what are you hearing from your sources about all these terror alert warnings, if you will, that are going out in advance of this July 4 weekend?

PEREZ: Well, Wolf, it definitely -- it extends beyond just ISIS' warnings and calls for attacks on social media.

[18:05:00]

We're told by law enforcement officials that part of it is also that the FBI and intelligence agencies have been monitoring communications and other sources to look for what they think might be on the mind of some of these people. There are hundreds of ISIS supporters who are being watched and there's definitely talk about carrying out an attack, if not now, some time during Ramadan, which continues, by the way, after July 4, and going further down the path towards the papal visit in September.

They know that something -- that there's talk of carrying something out.

BLITZER: Security's going to be intense here in the United States for a while.

PEREZ: Absolutely.

BLITZER: The Muslim holy month of Ramadan continues until around mid-July.

Evan, thanks very much.

Tonight, there's also new moves under way to protect American troops from a potential Fourth of July terror attack.

JIM SCIUTTO, CNN CHIEF NATIONAL SECURITY CORRESPONDENT: Wolf, this is just another sign of the lowered risk tolerance.

July 4 celebrations canceled at RAF, Royal Air Force Feltwell, in Norfolk, England. This is home to the U.S. Air Force 48th Fighter Wing. U.S. commanders there say a decision was made due to the most current local threat assessments after a meeting of their threat working group, the announcement making it very clear just what the stakes are, in their view, saying -- quote -- "We must make difficult decisions like this when lives are on the line."

Now, U.S. European Command tells us that this was a base decision, specific to this base. It's not U.K.-wide, it's not Europe- wide, but it does speak to the seriousness with which the U.S. military is taking the current terror threat, not just here in the U.S., but overseas.

And, little, arguably, the U.K. has a greater threat than the U.S., and there are many more known jihadis there, numbering in the thousands. So, that's really the way they're looking at the risk today.

BLITZER: Well, it's a big deal when the U.S. military does something like this, even at one base at Britain right now. Is it simply based on an abundance of caution?

Or was there something specific that we know of that caused this commander to say, you know what, the troops are not going to be able to participate in this July 4 celebration?

SCIUTTO: Not something specific that we know of. They won't say that there was a credible or specific threat to that base. But it is interesting, Wolf, that you have a number of bases around the U.K. with U.S. forces, and certainly a number around Europe, and the threat level in Europe is quite high now as well, arguably higher than it is in the U.S. with the number of jihadis there, proximity to Syria and Iraq, but it was this specific base making this specific decision.

Possibly they had an indication of something threatening them. But, listen, all base commanders make their own decisions. And this one base commander decided that the risk of having the event outweighed the benefits.

BLITZER: Yes, better to err on the side of caution, especially when we're dealing with this kind of a threat. Thanks very much, Jim Sciutto, for that.

Let's talk a little bit more about this July 4 terror threat.

Joining us, Senator James Lankford. He's a Republican of Oklahoma. He's also a member of the Senate Homeland Security Committee and the Senate Intelligence Committee.

Senator, thanks very much for joining us.

What do you make of these developments? Are you more concerned potentially, let's start off, with some sort of small-scale lone wolf attack, going after some sort of so-called soft target? Or is your greater concern something more complex, a larger, more coordinated terror attack that could kill potentially a whole lot more people?

SEN. JAMES LANKFORD (R), OKLAHOMA: The greatest concern is actually the lone wolf.

It's the individual that just decides to be inspired by ISIS. What they have done, ISIS is very well outspoken about how much they hate our freedom, who we are as Americans. So, July the 4th is one of those natural dates, while we're celebrating freedom, for them to be able to find some way to be able to poke us in the eye basically during that process.

ISIS has not typically done a lot of coordinated attacks. What they did in Egypt in the Sinai Peninsula is an anomaly in some ways. But most times, it's something closer to what happened in Garland, Texas, to inspire an individual, to be able to drive multiple states to be able to go and shoot and to be able to have some attack on a small scale.

That's the greater threat. It's also harder to be able to track.

BLITZER: Yes, in the Sinai, they -- what, they killed about 30 Egyptian soldiers in a very well-planned, coordinated military-type attack. That's obviously very worrisome.

Any specific threats -- I know you're well-briefed. Are there any specific, hard, concrete threats out there, some plot that the U.S., for example, got wind of?

LANKFORD: No, this is not about a specific threat. This is just ISIS in general.

We know they function on social media. And when they try to inspire people, they're very different than al Qaeda. Al Qaeda likes to coordinate, have a central command to be able to send out emissaries around that they have highly trained and say this is the moment we're going to do a large-scale attack.

ISIS is very different. They're reaching out on social media, telling people, it's a holiday, we ought to kill people, here's some ideas about how to do it, here's some places to be able to go. Just be able to go and do it. Here's our logo, put our logo up, tell them you're with us.

So, they're not looking to send people. They're looking to inspire people that already live among our midst. So, they're looking for people that have the same radical jihadi-type mind-set and say, join us in the worldwide fight and engage. That's why you see little pockets of ISIS all over the world doing these smaller-scale events.

[18:10:10] They're trying to inspire the same thing. And in fact they have

done it for several holidays. They have tried to do that. They have just been unsuccessful in trying to get it for several holidays, things like are Veterans Day, and others times, Memorial Day, when they were trying to inspire it. This is just one more time to do that.

I can tell you that the people of Oklahoma, the people that I'm around, we're going to continue to go out to events. We will be attentive to all those things, as we always are. But this is ISIS trying to instill fear, and that's not who we are as Americans.

BLITZER: And the good advice is, you see something, you say something. Hopefully, it will be a quiet, very nice July 4 holiday weekend.

LANKFORD: That's right.

BLITZER: What should the U.S. be doing to go after those ISIS commanders who are leading their social media campaign to go out there and inspire, if you will, ISIS sympathizers to launch these kinds of terror strikes?

We know the president is willing to order drone strikes to kill ISIS military commanders. What can the U.S. do to downgrade or destroy that social media capability, which clearly is very effective and inspiring ISIS supporters out there?

LANKFORD: Sure.

It is identifying those individuals, finding and locating those through social media. It's not always simple to do, but identifying those individuals that are actually inspiring this and to be able to engage. That takes great intelligence. That takes a lot of work to make sure that you're actually going after the right individual on this.

And, quite frankly, a lot of this is still driven by the instability in Syria as a whole. With Bashar Assad still leading Syria, there's still a tremendous number of individuals that would fight against ISIS, but as long as ISIS is fighting against Assad, they're going to leave ISIS alone and just continue to fight against Assad.

So, while Assad is still leading Syria, they feel like ISIS is not a threat to them personally. ISIS is a threat to Assad, and so they're going to ignore them. We need individuals in all these different groups focused on taking out ISIS. They're a worldwide threat.

But that also means that Assad needs to be replaced and needs to be gone and have a transition leadership in Syria to help get that.

BLITZER: We have much more to discuss, Senator, including the heightened security at U.S. military bases here in the United States and around the world -- much more with Senator Lankford when we come back.

(COMMERCIAL BREAK)

[18:17:02]

BLITZER: We're back with Senator James Lankford. He's a member of the Senate Homeland Security and Intelligence Committees.

We're talking about the Fourth of July terror threat, the unprecedented holiday security being put into place right now.

Senator, we also learned today that one of the ISIS leaders, a guy by the name of Tariq Al-Harzi, was killed in a coalition airstrike. He was known as the emir of suicide bombing. What do we know about this guy? The State Department had a $3 million bounty on his head.

LANKFORD: There are several individuals like him, Wolf, that are out there in the process that we're identifying. As we can identify their exact location, what they do, and how they're involved in the organization, we're trying to take some of those folks out.

You will remember about a month ago where we had the actual oil minister for ISIS that we actually went in and did a special operations raid in Syria to actually take the person out and then to be able to remove intelligence information from his home.

So this is a part of the ongoing strategy to be able to help identify those individuals, to be able to remove their leadership. ISIS has leadership, just like al Qaeda has leadership. It's important to be able to eliminate the individuals that are leading the organization. And it's also important that we actually take away the parameters of why they're trying to actually do this.

(CROSSTALK)

BLITZER: Senator, excuse me for interrupting.

You have no problem for the U.S. going out targeting these individuals and killing them?

LANKFORD: No, I do not, actually, on that, Wolf.

And the reason is, ISIS has been very clear that they want a worldwide jihadi movement to be able to overthrow multiple locations, and to be able to inflict as much terror, whether it be the United States, or our allies, all across the Middle East. We made that clear and obviously the threats that are coming down from July the 4th for us.

This is not a group that's just interested in Syria and Iraq. This is a group that is interested in worldwide domination and spreading this kind of hatred around the world. So it is important that the United States steps up and leads, because we cannot ignore real threats. Now, this was the same thing that we faced years ago with the Taliban and with al Qaeda, to say they're thousands and thousands of miles away, what does it matter to us, until they did a coordinated attack on American oil soil.

And we understand it does come to us, whether we want to pay attention to it or not.

BLITZER: Here in Washington today, Senator -- I know you're in Oklahoma, but here in Washington at the Navy Yard, we saw law enforcement come out in huge numbers responding what turned out to be fortunately a false alarm. But did we see an overreaction, an over- response?

(CROSSTALK)

LANKFORD: Actually, that's just a response you would expect in something like the Navy Yard, with the shooting that happened there before.

They're responding to it. It ended up being a large-scale drill, to say the least on it. It was a false alarm. But we actually saw law enforcement in a coordinated effort be able to respond to that in an entirely appropriate way for an active shooter.

Thankfully, there wasn't an active shooter there. But it is good to know that law enforcement has that kind of coordination and, in that moment, we do have appropriate response.

BLITZER: Is this the state of concern, the state of concern, what we call the new normal?

LANKFORD: It is for now. We're a nation that is still at risk.

[18:20:00]

And there is the sense among Americans that we can sit back because we're pulling out of Afghanistan, we're out of -- officially out of Iraq, in that zone. But Americans need to understand, there are people around the world that really do hate us, that really do hate our freedom.

It's difficult for us to be able to process because we're such a nation that has great care for people around the world. We do such incredible charity around the world. And we have this perception that we leave them alone, they leave us alone.

But we know very clearly from radical Islam that is not true. They actually develop worldwide recruits by attacking America and attacking the West. And the more that they can attack us and the more that they can poke us, the more that people that have that philosophy actually move to help them. So, attacking us is actually a recruiting element for ISIS, which seems completely foreign to us.

But we have to realize we are still a nation at risk and this is extremely important that we can still continue to defend ourselves and our families.

BLITZER: Should U.S. military bases here in the United States, including your home state of Oklahoma, where there are several major U.S. military facilities, should they be on a heightened state of security alert this weekend and maybe for the rest of Ramadan, the Muslim holy month of Ramadan, which goes through mid-July?

LANKFORD: There is always a perception that during Ramadan -- we have seen other attacks in previous years on that.

I know you had mentioned earlier about the base in the U.K. They saw base-specific things for them. They wanted to make that decision. But you will remember again about a month ago multiple bases went on heightened security because they sensed that there was a threat coming to bases.

That's not specific at this point to any of those bases. They would be on the same security status that they're always on and be as prepared as any other person in the United States would be.

Again, this is a group that's really energized by lone wolves, individuals that are unpredictable, that step out and say, I believe in this ISIS philosophy, this particular brand of radical Islam, and I want to go make a statement for ISIS.

So, this is not something that's highly coordinated in that. This is just a message to go out and say, if you hate America like we do, and you hate their freedoms, then step out and do what we do.

BLITZER: Senator Lankford, thanks very much for joining us.

LANKFORD: Thank you.

BLITZER: Let's hope it's a quiet and very peaceful July 4 holiday here in the United States, indeed around the world.

Just ahead, a pilot's fatal mistake now revealed. We have details of what he did wrong and his last words as his plane went down.

Plus, a twist in the D.C. mansion murder case, as the man accused of the gruesome killings now drops a courtroom bombshell.

(COMMERCIAL BREAK)

[18:26:55]

BLITZER: A stunning mistake by a pilot is now being blamed for a deadly plane crash that was all caught on camera; 43 people were killed when the TransAsia flight clipped a bridge and plunged into a river moments after taking off from Taiwan's capital.

Our aviation correspondent, Rene Marsh, is working the story for us.

So, Rene, we have learned new information. Tell us what we have learned.

RENE MARSH, CNN AVIATION CORRESPONDENT: Well, Wolf, this captain made a fatal mistake. Just seconds after takeoff, one engine failed. And while trying

to restart it, it -- he accidentally turned off the good engine for 46 seconds, causing the plane to lose power and eventually stall. It took two whole minutes before the pilots noticed the mistake. And in the words of the captain -- quote -- "Wow, pulled back the wrong-side throttle."

By then, Wolf, though, it was too late. I have to say, for a commercial pilot responsible for several lives on board to make a mistake like this, it truly is troubling. Loss of engine and recuperating from it, that is a basic part of training, especially for pilots here in the United States. The plane, we do know, could have flown with one engine.

But, as you know there, his fatal mistake, at one point, the plane had zero engine power.

BLITZER: Well, I guess the bottom-line question is, the pilot in this particular case, it's obviously very frightening, but the report reveals that the captain may not have been skilled enough to handle the problem that this plane was experiencing. That's pretty shocking.

MARSH: It is.

I mean, not only did he make this mistake of not -- of turning off the wrong engine, but according to this report, this pilot failed simulator training less than a year earlier, partly because he didn't master how to respond to the so-called engine flameout at takeoff.

He had to repeat this training, and eventually he passed the simulator check, making him qualified to become captain. But the instructors made several critical comments about his abilities. I'm going to quote some of them, one instructor saying -- quote -- that the captain was "prone to hesitation when facing situation that requires making decisions."

Another comment read, "Prone to be nervous and may make oral errors during the engine start procedure," not what you want to hear if you have a pilot who's flying passengers on a commercial flight.

I will point out, Wolf, this was an investigative update. The final report is due out April 2016.

Peter, the report, at least for now, stopped short of officially blaming, assigning blame, but it seems, based on what we just heard in Rene's report, that this seems to be a case of pilot error.

PETER GOELZ, CNN AVIATION ANALYST: We know what happened. This pilot made a serious, serious mistake. And what's shocking,

Wolf, is that there was another fully qualified pilot sitting to his right and the co-pilot was sitting on the jump seat. They had three fully qualified pilots. Not one of them intervened when the mistake was made.

BLITZER: And those lives were lost. Miles, we also learned from this report that the pilot of the aircraft, as Rene just pointed out, failed a flight simulator test back in May of 2014, less than a year before the accident. Should this pilot, I guess, have been allowed to fly after failing a test like this?

O'BRIEN: You know, Wolf, in a word, no. This is just heartbreaking, frankly. I mean, as passengers, when we get on board a commercial aircraft, an airliner, we expect a certain amount of capability out of the people flying the aircraft. And to read that this particular captain not only had a whole host of issues, nervousness and difficulties with checklists, but flunked this particular maneuver which led to the deaths of these passengers, is hard to imagine.

You know, we're talking about a part of the world, and Peter and I have talked about this quite a bit, where it's growing very rapidly. The airlines are growing rapidly. There's a demand for pilots. And I hope that these airlines learn the hard lessons that we've learned here in the United States about safety. I'm not certain they have.

BLITZER: Peter, here in America, what are the regulations if a pilot fails a simulator test along these lines, before that pilot could go out and actually pilot a plane?

GOELZ: Well, there's two things that goes on in the U.S. One is we learned this lesson back in the '90s. And pilots' training records used to kind of disappear. Now they follow you. If you have a bad training session, you could recover and get retested and get back into the cockpit. But if you show repeated problems, you're not going to get a job flying in the front of the plane.

And the thing that was shocking about this was that the Taiwanese government, the investigative agency, called on them to retest all their pilots. Ten of the pilots failed the test, 19 ducked the test. Almost 30 of them were fired. I mean, that airline should be shut down.

BLITZER: So I guess there's a lot of lessons we could learn from this, Miles. What's the major lesson you think everyone should learn from this tragic accident?

O'BRIEN: The bottom line, Wolf, is there's no free lunch in safety. Safety costs money. And when you have a huge demand for pilots and a competing demand for low ticket prices, there is tremendous pressure to cut corners on safety and training. And it's incumbent upon the regulatory bodies in these countries to step in. Because the free market ultimately will go to the bottom line, and the bottom line is not always going to be safe.

BLITZER: What do you think, Peter?

GOELZ: I agree with Miles 100 percent. I mean, there is such growth over there. There is a growing shortage of pilots. The regulatory agencies have got to step forward. They've got to demand competence.

BLITZER: Peter Goelz, thanks very much. Miles O'Brien, thanks to you, as well.

Just ahead, a real-life courtroom drama. Details of a surprise move by the man accused of one of the most gruesome crimes in recent Washington, D.C., history.

Plus how music may be helping Glen Campbell as he battles Alzheimer's. Our own Dr. Sanjay Gupta will take a closer look at the connection between music and memory.

(COMMERCIAL BREAK)

[18:38:23] BLITZER: A courtroom shocker in a case that rocked the nation's capital, the so-called D.C. mansion murders. The man accused of torturing and killing a wealthy Washington, D.C., family and their housekeeper made a move that caught everyone off guard.

Let's go to CNN's Tom Foreman. He's got details on what happened.

What have you learned, Tom?

TOM FOREMAN, CNN CORRESPONDENT: Wolf, when Daron Wint came to court today, we had no idea that what his attorney was going to suggest was basically that he was as surprised by these horrific murders as anyone else. But he didn't say that until that attorney was his former attorney.

(BEGIN VIDEOTAPE)

FOREMAN (voice-over): Wint came to court in handcuffs and shackles only to immediately break free of his legal team.

SEAN HANOVER, DARON WINT'S FORMER ATTORNEY: He was cooperative and forthcoming.

FOREMAN: Dropping defense attorney Sean Hanover for a public defender over what appears to be differences of opinion about how to fight the charges against Wint.

Outside the court, however, Hanover remained eager to at least unofficially defend his former client. Even as police say they have DNA, a boot print, and more linking Wint to the killings.

HANOVER: He was heartbroken like everybody else at their death. And I can assure you that he never intended or wanted anybody, them or anyone else, to be harmed.

FOREMAN: But the case against Wint goes beyond the evidence at the scene of the fire and murders. Officials say Wint, who was born in Guyana, was known as a troublemaker when he worked for Savvas Savopoulos the owner years ago.

CNN has learned Wint's green card was already in jeopardy earlier this year when he was arrested for receiving stolen property.

Still, the crime was complicated, and investigators suggest Wint had to have help. Sources tell CNN police are investigating Wint's brother and a cousin who also worked for Savopoulos and was also fired, threatening to burn the business in retaliation. But so far, no one else has been charged.

RON HOSKO, FORMER FBI ASSISTANT DIRECTOR: That part is concerning because certainly by now, they've had enough time to do lab examinations, to get records that typically in this case would be phone records that may put others in proximity to the crime scene, to try to lift fingerprints, get other DNA from the scene. Now the question is, does that exist?

HANOVER: He's not a violent guy.

FOREMAN: It could all play into the claim Hanover repeated even as he walked away from the case. His former client, he says, was set up.

(END VIDEOTAPE)

BLITZER: Interestingly, Hanover is not pointing at police when he talks about a setup. But rather at these so far shadowy, unknown, and unnamed accomplices -- Wolf.

BLITZER: So this lawyer says that he knows that other people were involved. Why isn't Wint hanging over, turning over these people to authorities?

BLITZER: Well, and there are sources close to the investigation who also say they really think there had to be other people involved.

The idea would be that maybe his legal team, with all these changes, has to finally settle down, figure out if there is a deal to be made. If there is a deal to be made that somehow he gets out from under the heaviest of these charges or gets some kind of special treatment, then maybe he starts giving up names, if there are names to give up.

So maybe that would explain why we haven't heard anything yet and why nobody else has been arrested, even though we're now talking about a considerable period of time, Wolf.

BLITZER: The mystery clearly continues. You'll stay on top of it for us. Tom Foreman, thanks very much.

On CNN this weekend, we're bringing you a very, very personal look at the challenges of Alzheimer's by following the journey of the country music legend Glen Campbell, who suffers from the disease. Right now we want to show you how music -- how music can be a remarkable source of joy and hope for Alzheimer's patients.

Here's our chief medical correspondent, Dr. Sanjay Gupta.

DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: Well, Wolf, we all know Alzheimer's is this cruel disease that robs you of the who's, the what's, the where's, the when's. But you're about to see just how music can bring memories flooding back in a way that nothing else can. So simple and so powerful.

(BEGIN VIDEOTAPE)

UNIDENTIFIED FEMALE: Hi, papa.

GUPTA (voice-over): I want to introduce you to Henry Drerer (ph).

UNIDENTIFIED FEMALE: How are you doing?

UNIDENTIFIED MALE: All right, fine.

GUPTA: But Henry is not fine. He's here in this nursing home suffering from Alzheimer's. He can no longer remember the who's, the what's, the where's. But famed neurologist Dr. Oliver Sacks is about to show us something truly remarkable.

OLIVER SACKS, NEUROLOGIST: We first see Henry inert, maybe depressed, unresponsive, and almost unalive.

UNIDENTIFIED FEMALE: Henry.

UNIDENTIFIED MALE: Yes?

UNIDENTIFIED FEMALE: Henry.

UNIDENTIFIED MALE: Yes?

UNIDENTIFIED FEMALE: I found your music.

SACKS: Then he is given an iPod containing, we know, his favorite music. And immediately, he lights up. His face assumes expression. His eyes open wide. And he's being animated by the music.

GUPTA: Dan Cohen is the founder of Music and Memory, the program that made it happen.

DAN COHEN, FOUNDER, MUSIC AND MEMORY: I heard a journalist on the radio talking about how iPod is ubiquitous. And I thought, well, the kids have them and many of us adults but nursing homes? Didn't seem from my experience likely. So I called a local nursing home and said, "I know music is already the No. 1 recreational activity, but can we see if there's added value to totally personalize the music?" They said yes. It was an instant hit.

GUPTA: The key word here is personalization.

Nancy Soletti is listening to one of her favorites, Johnny Cash.

Since her daughter, Alexandra, checked her into this facility last Christmas, Nancy's cognition has been rapidly declining. But music seems to rekindle something. Memories everyone else thought were lost and gone forever.

NANCY SOLETTI, ALZHEIMER'S PATIENT: For a while it would you can forget that you can't do what everybody else can do. And the music kind of brings thins back to you. It makes it familiar to you.

GUPTA: The thing that's so interesting about music is just how much of the brain it uses. Speaking the words comes from over here, the left temporal lobes. Putting them into a tune comes from over here, the right parietal lobe. Putting it all into rhythm, here, the cerebellum. Soon it's not just music you're talking about, it's an emotional response, which makes it that much harder to forget.

ALEXANDRA SOLETTI, NANCY'S DAUGHTER: It brings back who my mother is. And even if she can't -- at certain times can't remember either short or long-term memory, the minute that she hears the music, she remembers the words, incredibly.

[18:45:00] (SINGING)

GUPTA (voice-over): Nancy, Henry, and residents of more than 1,400 nursing homes around the country are having their brains re- awakened in a way with the answer to a simple question. What is your favorite song?

(SINGING)

GUPTA (on camera): I don't know about you, Wolf, but I often use headphones to tune out when I go for a run or when I'm on an airplane. But the nurses who have implemented this personalized music program tell me that it doesn't isolate their patients, it actually makes them more social.

I think this is a big step in the right direction. It's all about improving end of life care for dementia patients as well as their families -- Wolf.

(END VIDEOTAPE)

BLITZER: Excellent report from Dr. Sanjay Gupta. I totally, totally agree. I learned a lot from that. Good information.

By the way, for more on the battle against Alzheimer's, please be sure to watch CNN Films Presents, "Glen Campbell: I'll Be Me". It airs this Saturday night, 9:00 p.m. Eastern, only here on CNN.

Just ahead, some frightening moments on a flight to the U.S. capital. What forced the pilot to divert the plane?

And the GOP facing Trump trouble, fearing fallout from his remarks about Latino immigrants. Now, some Republicans are firing back. (COMMERCIAL BREAK)

[18:51:12] BLITZER: An airliner heading from St. Louis to here in Washington, D.C. made an emergency landing in Ohio after a passenger started making threats. The United Express plane landed in Ohio. A woman made threats about a bomb being on the plane. Out of an abundance of caution, the plane was diverted.

Authorities were waiting. The jet was parked on a remote part of the runway, while the plane was checked. No bomb or any other dangerous item fortunately turned up.

It's everything a presidential candidate could hope for. Crowds, donations and poll numbers are all on the rise for the Vermont Senator Bernie Sanders. He is campaigning as the anti-Hillary Clinton. And although she's still the frontrunner, Sanders is gaining considerable ground.

BRIANNA KEILAR, CNN SENIOR POLITICAL CORRESPONDENT: He is having quite the moment, Wolf, "Bernie-mentum" as it's being called. And it might not be enough to beat Hillary Clinton the way then-Senator Obama did in 2008, but it tells you a lot of Democratic voters want another option.

Enthusiasm for Sanders is helping his showing in states that drive the nomination process. In Iowa, Sanders jumped from 5 percent support in February to 15 percent in May, all the way to a respectable 33 percent, shrinking Clinton's lead by 26 points. And in New Hampshire, the wild-haired 73-year-old senator from neighboring Vermont has closed the gap to just eight points in the latest CNN/ORC poll.

His insurgent campaign bringing comparisons to fellow Vermonter Howard Dean's 2004 campaign effort. But like Dean, Sanders still faces long odds. Clinton crushes him in national polls by more than 40 points, and her campaign just announced a record-breaking $45 million fund-raising haul for her first quarter in the race, to Sanders' $15 million.

SANDERS: They may have the money, but we have the people. When the people stand together, we can win.

(END VIDEOTAPE)

KEILAR: We can win, that is still seen as very debatable, I will say.

But Bernie Sanders or maybe more accurately, those who support him, can certainly shape this race, pull Hillary to the left as we have seen him and those voters do, Wolf.

BLITZER: He's got impressive crowds. You got to give him a lot of credit for that. Stand by for a moment, Brianna.

He is getting 10,000 people showing up at a rally. You got to say, that's impressive.

BORGER: It is impressive. And, of course, it was a rally in Madison, Wisconsin. As Brianna pointed out, very liberal stronghold. He is doing well with liberal caucus goers in the state of Iowa, doubling his popularity since May.

This is a candidate that's kind of got no pretension.

[18:55:00] I think when you look at the comparison and the protectiveness that is around Hillary Clinton, look at Bernie, he goes out into the crowd and he is who he is. There's something about that that people like.

And also, he is playing to the left part of the left wing base of the Democratic Party. In certain places, it will work.

if he's a long-term threat. In the short-term, it's a threat in terms of the enthusiasm. I mean, at this point, she was hoping to sort of be -- you know, the one who is garnering the crowds.

One thing that's interesting, $15 million, that came in organically. That came in from people who are giving an average of $33.51. That means they can give again and again and again. So, that is actually more valuable than her $45 million, because it's worth more. And he has little overhead.

So, is he a threat? We're not sure. We will see how he organizes. But he is out there in Iowa for the next three or four days and I see young volunteers out there with clipboards signing up people's e-mail addresses and phone numbers. So, if they can organize this and harness this, he could be a threat.

But let's be a little bit more realistic about it -- I mean, she's probably more electable in the long run.

BLITZER: What are you hearing from inside the Clinton camp? How worried are they?

KEILAR: I think they are worried in that they would like that enthusiasm. And what it does is it reinforces that vulnerability of Hillary Clinton. I think they are sensitive to the fact that there isn't as much enthusiasm, that she doesn't have overflow crowds, for instance, even for her launch speech. But I also think that this could be worse for Hillary Clinton.

He really doesn't take big shots at her. He is running this very kind of civil campaign. And he doesn't want to -- look at Donald Trump. He calls Jeb Bush loser and weak. I mean, that is Donald Trump. But you don't see Bernie Sanders doing that. We will see if that happens.

ZELENY: He is getting --

BORGER: Right.

KEILAR: I think it reminds Hillary Clinton and her campaign that she is vulnerable in an area that she would have been vulnerable in whether it was Bernie Sanders or not. So, it's just reminding them that they need to protect that left flank. I think they better off having Bernie Sanders than an Elizabeth Warren.

BORGER: But if you look at that -- if you look at the Iowa poll, the truth of the --

BLITZER: The Quinnipiac.

BORGER: Right. The Quinnipiac poll, the truth of the matter is, is that Hillary Clinton remains hugely popular with the base. That's why they're not too worried, because while Bernie Sanders' popularity may be going up, so is hers. The base of the party likes her.

More important, they trust her. They also believe she could be elected president.

BLITZER: Let's talk about Donald Trump for a moment, Gloria. He is obviously doing very well in the polls nationally. In Iowa, in New Hampshire as well. Some of his comments on Mexican immigrants in the United States causing a backlash, causing some serious problems for Republicans.

How much of a problem is this for the GOP brand?

BORGER: You know, at first I think Republican candidates were trying not to pay any attention to Donald Trump. You know, they'd ask him about, they would shake their heads and go away. Now, they have to pay attention to him, because he is doing so well in the polls. And this is really bad news for the Republican National Committee that wanted to have a serious substantive sedate debate. Now, they've got Donald Trump in the sand box throwing the sand around at everybody else. And they are finding themselves in a situation where they have to respond.

We heard Chris Christie do that today, although he didn't take him on frontally, because he didn't want to get in a fight with Donald Trump. But they do have to pay attention.

ZELENY: There is. It's unusual. They are both of the same economic social class in New York City. That's part of it. But she was at his wedding in 2005.

And he's contributed money to the Clinton Foundation, $100,000, and to her campaigns over the years. So, there is a bit of a connection. And he has been largely a Democratic contributor throughout the years, which is why Republicans are sort of skeptical of him.

And he's not been as critical of Hillary during this period as he has been of some Republicans here. So, there are some Republicans who are skeptical or wondering what he is up to. Is he trying to mess around in this primary process?

But I suspect he will start attacking the Clintons here fairly quickly.

BORGER: And you want to talk about favorability? I mean, Bernie Sanders has great favorability in the Democratic Party. Donald Trump is upside down.

BLITZER: Quickly, Jim Webb, the former Virginia senator, he announces he is running for the Democratic presidential nomination.

KEILAR: That's right. Now, Jim Webb is barely registering in the polls. So, keep that in consideration. His avenue, as we see, is more for white voters, working class voters. Kind of the demo that Hillary Clinton would have been going for in 2007.

But he is still very far behind. We will see if he really gets his act together. So far, he hasn't.

BLITZER: All right. We'll see what happens, lots of politics as we go forward to 2016.

That's it for me. Thanks very much for watching.

Please tweet me @wolfblitzer. You can always tweet the show @CNNsitroom.